################################
# Outputs of the MARv3.5 model #
# by xavier.fettweis@ulg.ac.be #
#                              # 
#           06/10/2015         #
################################


All the files are here: ftp://ftp.climato.be/fettweis/MARv3/Greenland/


Information:
============

- MARv3.x uses the topography and ice sheet mask from Bamber et al. (2013).

- There are 2 sub-pixels for each land pixel in MARv3.x. The first one is 
covered by permanent ice and the second one by tundra. The variable 
MSK_MAR (between 1 end 2) gives the portion of the MAR pixel covered 
by permanent ice. In the NetCDF file, SMB is for the permanent ice covered 
area and SMB2 is for the tundra covered area.

-MARv3.x has been run at a resolution of 15, 20, ..., 35 km but corrections (based on local 
SMB gradient vs height) of SMB and run-off for taking into account the 
sub-grid 5 km topography from Bamber et al. (2013) are given in the monthly
mean files. The 5km interpolated fields are provided on the 5 x 5 km grid from Bamber at al. (2001).
These corrected SMB fields can be used for forcing ice sheet models at high resolution. 
In the NetCDF file, these corrected SMB fields are called SMBcorr, MEcorr, ... 

eg: SMBtotal = if(MSK_MAR ge 1) then (MSK_MAR-1)*SMB+(1-(MSK_MAR-1))*smb2

- the directory names are Forcing_periods_MARresolution

Forcing= ERA-Interim, NCEP-NCARv1, 20CRv2, GCMs from CMIP5, ...
Periods= between 1900 and 2100
MARresolution= mainly 10, 20, 25 km.  

In each directory, there are:

monthly_outputs_interpolated_at_5km : monthly MAR outputs interpolated at 5km (with corrections)
                                      the best data set for forcing ice sheet models

daily/hourly outputs can be requested to xavier.fettweis@ulg.ac.be

Grid/projection:
================

- If you use the 25 km MAR native outputs, the grid is

grid_mapping_name,stereographic "Stereographic Oblique Projection"
standard_name,stereographic "Stereographic Oblique Projection"
long_name,stereographic "Stereographic Oblique Projection"
longitude_of_projection_origin 40°W
latitude_of_projection_origin 70.5°N
false_easting -775 km
false_northing -1200 km
resolution 25km

- If you use the 25km outputs extrapolated to the 5 km grid, the 5 km grid is the one from Bamber et al. (2001):
http://nsidc.org/data/docs/daac/nsidc0092_greenland_ice_thickness.gd.html


Reference:
==========

You can freely use these MAR outputs just by citing

Fettweis, X., Box, J. E., Agosta, C., Amory, C., Kittel, C., and Gallée, H.: Reconstructions of the 1900–2015 Greenland ice sheet surface mass balance using the regional climate MAR model, The Cryosphere Discuss., doi:10.5194/tc-2016-268, in review, 2016.


but if I need to manipulate the MAR outputs for a paper or give you daily outputs, I usually ask to be a co-author of this paper.